FASTEC START project

We provided the research and development (R&D) consulting services for the later stages of Fastec START product’s development. These services were used to combine the various incomplete and undocumented product design revisions into a single final working, fully documented and manufacturable product.

The Fastec START product is used for powering 3-phase induction motors from a single phase supply. The START product first creates a magnetic field that is stored in the rotor, and then applies a very high starting torque to spin the rotor and any coupled mechanical load up to full operating speed to synchronise to the mains supply. This process is controlled through an advanced microprocessor system which we developed to resolve all the existing issues present in the previous designs of the product. Our review combined the best aspects of several design revisions into a new design.

This product starts induction motors with reduced inrush current allowing the motors to run from poor quality supplies including small single phase generators that are of a similar power rating to that of the motor. The Fastec START technology provides a range of advantages such as not introducing harmonic distortion, EMI (Electromagnetic Interference) or RFI (Radio Frequency Interference) while the motor is running.

Our services were also used to develop advanced features for both hardware and software to resolve and diagnose outstanding issues. These included:

– Task system for ensuring real time response behaviour for electronics control,

– Advanced software inverse time current overload protection to allow configurable protection against incorrectly wired or overloaded motors. This also now allows protection discrimination for various models designed.

The new design also included the following changes to the hardware:

– Improved reliability – profiling the electronics to ensure components are operating within their parameters, redesigning sections of the power electronics to resolve all out of specification operating modes.

– Ease of manufacturing – redesigned the user interface to remove all the internal wiring and redesigned the mechanical assembly to remove the metal frame and reduce the amount of mechanical assembly required.

– Cost reduction of the design – optimising components used, reducing the number of circuit boards required and assembly time.

– Improved energy efficiency – reducing control circuits operational power by over 85%, removing the need for active or passive heat removal, also performed Infra-Red captures of the PCB (Printed Circuit Board) highlighting inefficient areas. This saved power came from improving the design of various components and circuits including – SMPS (Switch Mode Power Supply), transformers, relay driving, SCR (Silicon Controlled Rectifier) driving and most importantly major improvements in the software control. Previously components were recorded as reaching temperatures over 100⁰C and now all components operate below 50⁰C.

– Improved performance understanding – though the diagnostics tools developed, features were implemented to allow profiling of starting (calibration time, rotation speed, start capacitors voltage, and inrush current measured) and running (currents measured) performance of various setups. The start and run capacitors have also been optimised to allow various motors and applications to start and run successfully. We also modelled the starting performance by way of the rotor’s inertia and the motors efficiency of the starting current leading to the torque generated.

– Improved operating conditions – allowed operating from generator (genset) by filtering both the mains and rotor synchronising signals and dynamically updating synchronising rotor speed based on generator speed, also allowing both 50Hz and 60Hz operation.

– EMC Compliance – R&D compliance EMC (Electromagnetic Compatibility) testing and filtering of the analysed noise paths. Developed a unique model for analysing and filtering out the conducted emission noises dynamically generated at each stage of starting a motor. We analysed these in both the time and frequency domain using our electronics lab equipment.

– Future proof design – Included redundant opto-coupled I/O interface for more advanced features to be developed later in the software and also separated out the motor and control powers to allow 2-phase 400V motor operation without future board revisions.

The Fastec START product won the New Zealand Engineering Excellence Award for Energy Systems.